Valve stems are known in the art for tubeless tires. In a tubeless tire and wheel rim assembly, the tire is so constructed as to conform to the rim of a wheel to form an air-tight seal with the rim. To inflate the tire, a separate valve stem is typically seated in an airtight fashion to an opening in the rim.
A typical valve stem assembly has a hollow metal tube disposed within and bonded to a rubber sleeve. Frequently, the rubber sleeve has at its end directed to the interior of the tire an enlarged flange or base adapted to sealingly engage at least the interior surface of the wheel rim around the opening as air pressure is applied thereto. At its end directed to the exterior of the wheel rim, the metal tube projects beyond the rubber sleeve and is usually provided with external threads for retaining a valve cap and interior threads for retaining an air valve. See generally, U.S. Pat. No. 4,807,343. In this configuration, prior art valve stems generally must be installed by inserting them through the opening from the inside of the wheel rim and pulling them into position from the outside. One of the difficulties with this type of arrangement is that installing a valve stem or replacing a defective valve stem in the manner described above requires, by necessity, that the tire be removed from the rim, or at least that the tire bead be broken free from the rim to provide access to the wheel rim interior for insertion of the new stem. Tire demounting and remounting requires specialized equipment, skilled personnel, vehicle downtime and expense.
Various efforts have attempted to address this and other deficiencies in the art. Some tubeless tire valves have been developed with specific configurations that allow for exterior wheel rim mounting. See, for example, U.S. Pat. Nos. 2,634,785; 2,866,492; 2,872,963; 2,966,191; 3,258,051; 3,368,603; 3,863,697; and 4,016,918, the specifications of which are incorporated herein in their entirety. Despite these attempts, further advances are possible and desired. Such externally mountable valve stems have not proven entirely satisfactory. Specialized equipment and skilled personnel are still needed to properly externally mount a replacement valve stem. A further deficiency of these externally mountable valve stems is the frequent difficulty in obtaining a proper seal between the rubber sleeve of the valve stem assembly to the metal wheel rim.